What Does Rgbm Stand For Diving?

The Wienkes RGBM model is a dual-phase approach used in decompressing divers under various conditions, including multi-day, multi-level, repetitive, non-stop, altitude, decompression, mixed gas, and saturation diving. It assumes that during short nonstop air diving, the RGBM reproduces the Spencer limits. For multidiving in spans shorter than 1-3 hours, the RGBM reduces nonstop limits by 10%. Suunto RGBM is a pioneering algorithm for managing dissolved and free gas in blood and tissue.

RGBM stands for Reduced Gradient Bubble Model, invented by Bruce Wienke and used in several dive computers, such as Suunto Vyper Air, Vyper, Cobra, Cobra3, Zoop, D4i, and D6i. It is based on the Buhlmann algorithm and classical VPM bubble theory. The model addresses coupled issues of gas uptake and elimination, bubbles, and pressure changes in different computational frameworks.

The Reduced Gradient Bubble Model (RGBM) was developed by Bruce Wienke and is based in part on the Buhlmann algorithm and the classical VPM bubble theory. It is a modern one, treating the many facets of gas dynamics in dive computers. Suunto Cressi computers come with the Haldane and Wienke RGBM algorithm, which is similar to the one Suunto uses but is known to be rather conservative.

In summary, the Wienkes RGBM model is a widely-used decompression algorithm used in various dive computers, such as Suunto Vyper Air, Vyper, Cobra, Zoop, D4i, and D6i, and is used more at a recreational level.

How is RGBM different from VPM?

The Reduced Gradient Bubble Model (RGBM)was developed by Dr. Bruce Wienke and based in part on the Buhlmann algorithm and the classical VPM bubble theory. It is, however, conceptually different from the latter in that it rejects the gel-bubble parametrizations. The RGBM is characterized by the following assumptions:

What does EFR mean in diving?

In the Emergency First Response (EFR) you will learn primary care, basic first Aid and CPR and secondary care, injury and illness assessment and bandaging. This is all at a reduced rate when combined with the Rescue Diver course.

PADI Advanced Open Water Diver or Junior Advanced Open Water (or have a qualifyingcertification from another training organization)

An appropriate certification in first aid and CPR within the previous 24 months.

Be medically fit to dive, please carefully read the medical declaration below.

What is the difference between the RGBM and the Bühlmann algorithm?

RGBM uses a bubble model to calculate decompression and incorporates a slower ascent with deeper stops. Buhlmann uses a dissolved gas model to calculate decompression and incorporates a faster ascent followed by longer stops at shallower depths.

All decompression models, starting with that of John Scot Haldane, have purported to be based on a theoretical model. John Scot Haldane’s was established on an idea of limited, but stable, supersaturation. This notion persisted into the 1990s. While incorrect, it has the clear ability to generate tables for decompression, and it allows extrapolation to deeper depths and longer bottom times. This idea, for example, was the basis for the US Navy dive tables.

The major problem with the stable supersaturation concept was that a free gas phase could (supposedly) form with very limited dissolved nitrogen supersaturations. This is not in agreement with theory or experiment. Typically, several tens – if not hundreds – of atmospheres of supersaturation are needed to form gas bubbles in water. Water is a liquid with a very high cohesive force between its molecules, and voids do not form within it with ease. The dissolved nitrogen oversaturations in diving are slight and not capable of (de novo) bubble formation.

The solution to this dilemma was to introduce into diving the concept of preformed tissue micronuclei. These preformed nuclei were accepted in virtually ever endeavor (even baking) with the exception of diving and, their acknowledgment was a late arrival on the scene.

What is the best algorithm for diving?

• Bühlmann Algorithm: Developed by Dr. Albert A. Bühlmann, this algorithm is based on a series of tissue compartments that represent different parts of the body. Each compartment absorbs and releases gas at different rates. The Bühlmann algorithm calculates safe ascent rates and decompression stops based on these rates, making it one of the most widely used models in recreational and technical diving.
• VPM (Varying Permeability Model): The VPM takes into account the formation of microbubbles in the body during a dive. Instead of preventing all bubble formation, as traditional models do, the VPM allows for controlled microbubble formation, leading to potentially shorter decompression times.
• RGBM (Reduced Gradient Bubble Model): A hybrid model, the RGBM combines elements of both the Bühlmann and VPM algorithms. It focuses on minimizing bubble formation in the body, especially in the “silent” or asymptomatic phase, where bubbles are present but not causing symptoms.

Factors Influencing Algorithm Calculations. While dive algorithms are based on scientific principles and extensive research, they also account for various external and individual factors that can influence gas absorption and release. Some of these factors include:

• Water Temperature: Colder water can affect circulation, potentially slowing down the release of inert gasses from the body. Some dive computers adjust their calculations based on water temperature to account for this.
• Previous Dives: Repetitive dives or dives conducted over multiple days can lead to residual nitrogen in the body. Algorithms take into account the history of recent dives to provide accurate dive profiles.
• Altitude: Diving at higher altitudes, such as in mountain lakes, affects ambient pressure. Dive computers equipped with altitude adjustments modify their algorithms to ensure safe diving in these environments.
• Individual Physiology: Some modern dive computers allow divers to adjust the conservatism settings. Divers who feel they might be at higher risk, due to factors like age or fitness level, can choose a more conservative algorithm setting for added safety.

What is the 1 3 rule in diving?

In technical diving, the 1/3 Rule ensures divers have enough gas for the descent, return, and emergencies. It divides the total gas supply into three parts: one-third for the descent and exploration, one-third for the return, and one-third as a reserve, enhancing safety in challenging environments.

Whether you’re an experienced technical diver exploring deep wrecks and caves or a recreational diver enjoying the beauty of coral reefs, managing your gas supply is paramount for a safe diving experience. The 1/3 Rule is a fundamental guideline that helps divers allocate their gas effectively, ensuring enough supply for descent, exploration, and emergencies.

What is the 1/3 Rule?. The 1/3 Rule is an essential guideline in scuba diving, especially in technical diving, designed to ensure that divers have enough breathing gas for their underwater journey. According to this rule, a diver should divide their gas supply into three equal parts:

• One-third for the descent and exploration phase.
• One-third for the return to the surface.
• One-third as a reserve for emergencies.

What is the fastest decompression algorithm?

As outlined, there are often drastic compromises between speed and size. The fastest algorithm, lz4, results in lower compression ratios; xz, which has the highest compression ratio, suffers from a slow compression speed. However, Zstandard, at the default setting, shows substantial improvements in both compression speed and decompression speed, while compressing at the same ratio as zlib.

While pure algorithm performance is important when compression is embedded within a larger application, it is extremely common to also use command line tools for compression — say, for compressing log files, tarballs, or other similar data meant for storage or transfer. In these cases, performance is often affected by overhead, such as checksumming. This chart shows the comparison of the gzip and zstd command line tools on Centos 7 built with the system’s default compiler.

The tests were each conducted 10 times, with the minimum times taken, and were conducted on ramdisk to avoid filesystem overhead. These were the commands (which use the default compression levels for both tools):

What is the best diving decompression algorithm?

• Bühlmann Algorithm: Developed by Dr. Albert A. Bühlmann, this algorithm is based on a series of tissue compartments that represent different parts of the body. Each compartment absorbs and releases gas at different rates. The Bühlmann algorithm calculates safe ascent rates and decompression stops based on these rates, making it one of the most widely used models in recreational and technical diving.
• VPM (Varying Permeability Model): The VPM takes into account the formation of microbubbles in the body during a dive. Instead of preventing all bubble formation, as traditional models do, the VPM allows for controlled microbubble formation, leading to potentially shorter decompression times.
• RGBM (Reduced Gradient Bubble Model): A hybrid model, the RGBM combines elements of both the Bühlmann and VPM algorithms. It focuses on minimizing bubble formation in the body, especially in the “silent” or asymptomatic phase, where bubbles are present but not causing symptoms.

Factors Influencing Algorithm Calculations. While dive algorithms are based on scientific principles and extensive research, they also account for various external and individual factors that can influence gas absorption and release. Some of these factors include:

• Water Temperature: Colder water can affect circulation, potentially slowing down the release of inert gasses from the body. Some dive computers adjust their calculations based on water temperature to account for this.
• Previous Dives: Repetitive dives or dives conducted over multiple days can lead to residual nitrogen in the body. Algorithms take into account the history of recent dives to provide accurate dive profiles.
• Altitude: Diving at higher altitudes, such as in mountain lakes, affects ambient pressure. Dive computers equipped with altitude adjustments modify their algorithms to ensure safe diving in these environments.
• Individual Physiology: Some modern dive computers allow divers to adjust the conservatism settings. Divers who feel they might be at higher risk, due to factors like age or fitness level, can choose a more conservative algorithm setting for added safety.

What algorithm does Aqualung use?

Pelagic Z+ Aqualung: Pelagic Z+ – a proprietary algorithm developed by Dr. John E. Lewis, based on Bühlmann ZH-L16C algorithm. Conservatism may be adjusted by altitude setting, deep stops, and safety stops.

Hydrospace Explorer Trimix and rebreather dive computer. Suunto Mosquito with aftermarket strap and iDive DAN recreational dive computers.

A dive computer, personal decompression computer or decompression meter is a device used by an underwater diver to measure the elapsed time and depth during a dive and use this data to calculate and display an ascent profile which, according to the programmed decompression algorithm, will give a low risk of decompression sickness. A secondary function is to record the dive profile, warn the diver when certain events occur, and provide useful information about the environment.

Most dive computers use real-time ambient pressure input to a decompression algorithm to indicate the remaining time to the no-stop limit, and after that has passed, the minimum decompression required to surface with an acceptable risk of decompression sickness. Several algorithms have been used, and various personal conservatism factors may be available. Some dive computers allow for gas switching during the dive, and some monitor the pressure remaining in the scuba cylinders. Audible alarms may be available to warn the diver when exceeding the no-stop limit, the maximum operating depth for the gas mixture, the recommended ascent rate, decompression ceiling, or other limit beyond which risk increases significantly.

What is the 120 rule in scuba diving?

The simplest form of dive bezel is used in conjunction with a set of tables that indicates the no-decompression limit for each depth. You set the zero mark (usually an arrow) opposite the minute hand, and as time passes, the dive time is shown on the bezel. Knowing the maximum time allowable against the maximum depth indicated on a depth gauge makes for a safe dive. There is an old and questionably reliable rule, known as the “120 Rule” that says if you subtract your max depth from 120, you’ll get your no-deco time. So an 80-foot dive gives you 40 minutes before it’s time to head back to the surface. In a pinch, sure, but multi-level diving and time spent at each depth also plays a factor.

The author with a Rolex Submariner on one wrist and decompression plan slate on the other.

A step beyond the simple elapsed time bezel is the so-called “no-deco” bezel, patented by Doxa in 1967. This double scale bezel takes the place of those clunky and not exactly waterproof tables, by engraving the no-deco limits right on the outer ring. Set the zero mark to the minute hand when you descend, and the scale indicates when to surface for depths from 60 feet (60 minutes) down to 190 feet (4 minutes). This bezel type was also adopted by other brands like Eterna and Heuer, and is mainly aimed at the sport diver, who is sticking to recreational depths and doing strictly no-decompression diving. Similarly, Citizen printed the no-deco limit scale on the rubber strap provided with its Aqualand dive watches of the 1980s.

What does BCD mean in diving?

Imagine scuba diving while hovering, weightless underwater – eye to eye with a fish. How is it possible? It starts with your buoyancy control device (BCD).

A BCD does exactly what its name describes – it gives you control in the water. Sometimes you want to float on the surface comfortably. Occasionally, you want to kneel or stand on the bottom, sometimes during a training course. Most of the time, you want to drift along effortlessly mid-water, observing the scenery. To do this efficiently, you need a BCD that fits you well, along with a weight system to fine-tune your buoyancy. The BCD also holds your tank. Visit your PADI Dive Center or Resort to get advice about BCDs.

• Expandable bladder
• Low-pressure inflator and oral inflation mechanism
• Deflator mechanism and overpressure valve
• Adjustable straps, buckles, bands or releases
• Adjustable tank band and sturdy back plate

• BCD Styles. Jacket style – most popular for recreational scuba diving. Some made specifically for women.
• Wing (back-mount) style
• Traveling BCDs – made of lighter materials
• Technical diving systems combine wing-style bladders with harness setups
• Sidemount divers combine a back wing with a harness system that mounts tanks to your sides.

What does spg in diving stand for?

Submersible Pressure Gauge SPG (Submersible Pressure Gauge) The Essentials. Know how much air is left in the tank. A SPG can be separate or built into a dive computer and are made in both analog and digital.

Know how much air is left in the tank. A SPG can be separate or built into a dive computer and are made in both analog and digital.

Description. Your SPG displays how much air remains in your tank so that you can end your dive well before you get too low. An SPG can either be a mechanical gauge connected by a hose that reads the pressure in bar (metric) or psi (imperial, pounds per square inch) in your tank, or it may be built into your dive computer. Visit your PADI Dive Center or Resort to get advice about the right SPG for you.

• Easy to read and understand, because you use your SPG constantly during a dive to monitor your air supply.
• Securely attached so you can quickly and easily find it. Plus, you don’t want your SPG dangling, causing drag, hitting sensitive aquatic life or becoming damaged.